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From: Dave Jones <davej@redhat.com>
To: Bodo Eggert <7eggert@gmx.de>
Cc: mingo@redhat.com, Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: Shrink the held_lock struct by using bitfields.
Date: Tue, 2 Jan 2007 20:06:31 -0500	[thread overview]
Message-ID: <20070103010631.GA11031@redhat.com> (raw)
In-Reply-To: <E1H1uI5-0000mn-0j@be1.lrz>

On Wed, Jan 03, 2007 at 01:47:36AM +0100, Bodo Eggert wrote:
 > Dave Jones <davej@redhat.com> wrote:
 > 
 > > Shrink the held_lock struct by using bitfields.
 > > This shrinks task_struct on lockdep enabled kernels by 480 bytes.
 > 
 > >  * The following field is used to detect when we cross into an
 > >  * interrupt context:
 > >  */
 > > -     int                             irq_context;
 > [...]
 > > +     unsigned char irq_context:1;
 > [...]
 > 
 > Can these fields be set by concurrent processes, e.g.:
 > CPU0        CPU1
 > load flags
 >             load flags
 >             flip bit
 >             store
 > flip bit
 > store

It's a per-process structure.

		Dave

-- 
http://www.codemonkey.org.uk

  reply	other threads:[~2007-01-03  1:06 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <7z1oG-6Jr-5@gated-at.bofh.it>
2007-01-03  0:47 ` Shrink the held_lock struct by using bitfields Bodo Eggert
2007-01-03  1:06   ` Dave Jones [this message]
2007-01-02 23:35 Dave Jones
2007-01-02 23:38 ` Dave Jones
2007-01-14 18:45   ` Ingo Molnar

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